The best 13 out of the 26 Time Management Hacks of Etienne Garbugli:

1. only plan for 4-5 hours of real work per day
2. it’s normal to have days where you just can’t work and days when you will work 12h. Work more when you’re in the zone; relax when you’re not
3. don’t multitask. focus!
4. you’re always more focused and productive with limited time
5. start with short tasks. 7 Reasons Why You Should Tackle Hard Problems Last
6. “Done is better than perfect” (*) – iterate
7. separate thinking and execution
8. organize important meetings early in the day. “Every meeting has to have a leader, a stated purpose, a start and end time, and a valid reason for each and every person to be there. The leader documents conclusions, plans, action items, whatever, then follows up.” – Remember This Simple Equation To Run Great Meetings
9. break big tasks into small ones
10. always prioritize
11. if it can be done 80% by someone else, delegate it!
12. use apps for reminders. Don’t trust your brain for memorizing
13. write down everything that distracts you. If you write them down, they’ll stop bubbling up when you’re in the zone

Read the other half on Slideshare: 26 Time Management Hacks I Wish I’d Known at 20

(*)Hackers try to build the best services over the long term by quickly releasing and learning from smaller iterations rather than trying to get everything right all at once. To support this, we have built a testing framework that at any given time can try out thousands of versions of Facebook. We have the words “Done is better than perfect” painted on our walls to remind ourselves to always keep shipping.
– Letter from Mark Zuckerberg